CN114427745B - Intelligent oil return control method of compressor and variable frequency air conditioner - Google Patents
Intelligent oil return control method of compressor and variable frequency air conditioner Download PDFInfo
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- CN114427745B CN114427745B CN202210152528.5A CN202210152528A CN114427745B CN 114427745 B CN114427745 B CN 114427745B CN 202210152528 A CN202210152528 A CN 202210152528A CN 114427745 B CN114427745 B CN 114427745B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
- F24F11/63—Electronic processing
- F24F11/64—Electronic processing using pre-stored data
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B31/00—Compressor arrangements
- F25B31/002—Lubrication
- F25B31/004—Lubrication oil recirculating arrangements
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
- F25B43/02—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat for separating lubricants from the refrigerant
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2500/00—Problems to be solved
- F25B2500/16—Lubrication
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
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- Thermal Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Signal Processing (AREA)
- Mathematical Physics (AREA)
- Fuzzy Systems (AREA)
- Analytical Chemistry (AREA)
- Power Engineering (AREA)
- Control Of Positive-Displacement Pumps (AREA)
Abstract
The application provides an intelligent oil return control method of a compressor and a variable frequency air conditioner, wherein the control method comprises the following steps of S1, starting the compressor and continuously running for t0 time, and entering intelligent oil return control; step S2, measuring the oil level H of lubricating oil in an oil separator; and step S3, controlling the running frequency f of the compressor according to the oil level height H, wherein the intelligent oil return control method of the compressor and the variable frequency air conditioner have the advantages of high reliability, energy conservation and comfort.
Description
Technical Field
The application relates to the field of air conditioners, in particular to an intelligent oil return control method of a compressor and a variable frequency air conditioner.
Background
In the operation process of the variable frequency air conditioner, refrigerant is compressed into high-temperature and high-pressure gas in the compressor, and part of lubricating oil can be taken away when the refrigerant is discharged from the exhaust port of the compressor, and the lubricating oil is gradually deposited in parts such as an evaporator, a condenser and a connecting pipe in a layered manner along with the circulating flow of the refrigerant, so that on one hand: the lubricating oil stored in the heat exchanger, the connecting pipe and other parts can influence the use effect of the air conditioner; on the other hand: the lack of lubricating oil in the compressor results in poor lubrication, increased wear and serious influence on the service life of the compressor.
At present, a common oil return method for a compressor in a variable frequency air conditioner is to change the compressor into high-frequency operation at regular time and perform forced oil return, but the oil return method has the following defects because the lubricating oil quantity in the compressor cannot be monitored in real time:
first, the energy consumption is high: the oil is returned by the compressor in a timing frequency-rising way, so that the energy consumption is increased and the energy waste is easily caused when the oil is not needed to return;
second, poor comfort: the fluctuation of indoor temperature is larger when the compressor returns oil, and the use comfort of a user is affected;
third, reliability is low: the compressor can not effectively identify the oil level, and oil is not returned when oil return is needed, so that the reliability of oil return is affected.
Therefore, the oil return method of the compressor of the variable frequency air conditioner, particularly the oil return reliability is one of the difficulties in the industry, and is of great importance to the service life of the compressor, and the oil return control method of the compressor capable of effectively improving the reliability, the energy conservation and the comfort is a technical problem to be solved by the person skilled in the art.
Disclosure of Invention
The application designs an intelligent oil return control method of a compressor and a variable frequency air conditioner, which are used for solving the problems of poor reliability, energy conservation and comfort in the oil return process of the existing compressor.
In order to solve the problems, the application discloses an intelligent oil return control method of a compressor, which comprises the following steps of S1, starting the compressor and entering intelligent oil return control after continuously running for t0 time;
step S2, measuring the oil level H of lubricating oil in an oil separator;
step S3, controlling the operation frequency f of the compressor according to the oil level height H.
In the intelligent oil return control method of the compressor, intelligent oil return control is not performed immediately after the compressor is started, and the intelligent oil return control is performed after the compressor is started, so that the compressor is unstable in operation and in an unstable starting operation state in a period of time just after the compressor is started, the accuracy of oil return control is affected when the intelligent oil return control is performed, the time t0 is generally short, the risk of poor oil return of the compressor is low, and therefore the intelligent oil return control is performed after the compressor is started and continuously operated for the time t 0.
Further, in the step S2, the oil level H of the lubricating oil in the oil separator is measured by an oil level sensor.
The oil level sensor is used for measuring the oil level H of the lubricating oil in the oil separator, so that the oil level sensor is simple, convenient and quick, and the data is real and reliable.
Further, the oil level sensor is arranged on an oil separator, the oil level sensor comprises a positive electrode and a negative electrode, and lubricating oil in the oil separator has conductivity;
when lubricating oil exists between the anode and the cathode of the oil level sensor, the oil level sensor is conducted;
and when no lubricating oil exists between the anode and the cathode of the oil level sensor, the oil level sensor is disconnected.
The oil level sensor realizes switching of on-off states by utilizing conductivity of lubricating oil, so as to indicate the height of the oil level, and the oil level sensor is ingenious in design, simple and easy to realize.
Further, a plurality of oil level sensors are arranged in the oil separator, the plurality of oil level sensors are distributed at different heights along the vertical direction, and the control unit of the variable frequency air conditioner judges the oil level height H in the oil separator according to the on-off states of the plurality of oil level sensors.
Through the arrangement of a plurality of oil level sensors, the oil level height can be limited in a smaller interval, so that the oil level height can be indicated more accurately.
Further, the oil level height H in the oil separator is between the highest oil level in the on oil level sensor and the lowest oil level in the off oil level sensor.
When lubricating oil exists between the anode and the cathode of the oil level sensor, the oil level sensor is conducted; when no lubricating oil exists between the anode and the cathode of the oil level sensor, the oil level sensor is disconnected, and therefore, the oil level height H is between the highest oil level in the oil level sensor which is connected and the lowest oil level in the oil level sensor which is disconnected.
Further, 4 oil level sensors are arranged in the oil separator, the installation heights of the 4 oil level sensors are H1, H2, H3 and H4 respectively, wherein H1 > H2 > H3 > H4, the oil level height H in the oil separator is divided into 5 state sections according to the on-off states of the 4 oil level sensors, and the sections are sequentially from high to low: h is more than or equal to H1, H1 is more than or equal to H2, H2 is more than or equal to H3, H3 is more than or equal to H4 and H4 is more than or equal to H.
The oil level height H is divided into 5 state intervals through the arrangement of 4 oil level sensors, and a foundation is provided for the follow-up differentiated oil return control.
Further, in the step S3, the process of controlling the operating frequency f of the compressor according to the oil level height H includes:
when the oil level height H is more than or equal to H1, the compressor does not perform frequency-boosting oil return;
when the oil level height H1 is more than H and is more than or equal to H2, the compressor returns oil at regular time, and the oil return frequency is f3;
when the oil level height H2 is more than H and is more than or equal to H3, the oil is returned to the compressor at regular time, and the oil return frequency is f4;
when the oil level height H3 is more than H and is more than or equal to H4, the oil is returned to the compressor at regular time, and the oil return frequency is f5;
when the oil level height H4 is more than H, the compressor immediately returns oil, and the oil return frequency is f5;
wherein f3, f4 and f5 are preset frequency values, and f3 is smaller than f4 and smaller than f5.
According to the application, the oil level H of the lubricating oil in the oil separator is measured, and then the operating frequency f of the compressor is controlled in real time according to the oil level H, so that the operating frequency f of the compressor is closely combined with the oil level H of the lubricating oil in the oil separator, and is closely related to the oil level H, oil return is carried out according to the proper frequency only when oil return is needed, and the problems of high energy consumption, poor reliability and low comfort caused by the fact that forced oil return is carried out blindly according to the parameters such as the operating time, the operating frequency, the exhaust temperature, the air inlet temperature, the exhaust pressure and the exhaust volume of the compressor in the prior art are avoided, and the oil return is not carried out when oil return is not needed, and the compressor needs to be quickly switched to high-frequency operation in the oil return process are caused.
Further, the value of the oil return frequency f3 is 60-65 Hz; the value of the oil return frequency f4 is 68-72 Hz; the value of the oil return frequency f5 is 75-80 Hz.
Through the differentiation setting of oil return frequency under different oil level heights H, can compromise travelling comfort and energy-conserving nature for air conditioner oil return control is more accurate, and the influence on the air conditioner operation process is lower.
Further, in the step S3, the process of timing oil return of the compressor includes: when the running frequency f of the compressor is lower than the accumulated time of the preset threshold f1 and reaches t1 time, the compressor enters into the ascending oil return operation, and the oil return time is t2 each time.
By timing oil return, the method can save and simplify the program, and simultaneously, the method can be combined with the mode of determining the oil return frequency according to the oil level height H differentiation, so that a simple, convenient and accurate oil return control method can be provided.
A variable frequency air conditioner adopts the intelligent oil return control method to return oil to a compressor.
The intelligent oil return control method of the compressor and the variable frequency air conditioner have the following advantages: according to the application, the oil level H of the lubricating oil in the oil separator is measured, and then the operating frequency f of the compressor is controlled in real time according to the oil level H, so that the operating frequency f of the compressor is closely combined with the oil level H of the lubricating oil in the oil separator, and is closely related to the oil level H, oil return is carried out according to the proper frequency only when oil return is needed, and the problems of high energy consumption, poor reliability and low comfort caused by the fact that forced oil return is carried out blindly according to the parameters such as the operating time, the operating frequency, the exhaust temperature, the air inlet temperature, the exhaust pressure and the exhaust volume of the compressor in the prior art are avoided, and the oil return is not carried out when oil return is not needed, and the compressor needs to be quickly switched to high-frequency operation in the oil return process are caused.
Drawings
FIG. 1 is a schematic diagram of a prior art compressor oil return process;
fig. 2 is a schematic structural diagram of a variable frequency air conditioner according to the present application;
FIG. 3 is a schematic view showing the external structure of an oil separator according to the present application;
FIG. 4 is a schematic view of the internal structure of an oil separator according to the present application;
FIG. 5 is a schematic view of the cross-sectional structure in the direction A-A in FIG. 4;
fig. 6 is a schematic view of a cross-sectional structure in the direction B-B in fig. 4.
Reference numerals illustrate:
1. an evaporator; 2. a condenser; 3. a compressor; 301. a compressor body; 302. an oil separator; 3021. an air outlet pipe; 3022. an oil return pipe; 3023. a lower end cap; 3024. a middle cylinder; 3025. a first filter screen; 3026. SUS filaments; 3027. an upper end cap; 3028. a second filter screen; 3029. an air inlet pipe; 303. a gas separator; 304. an oil return capillary; 4. a control valve; 401. a four-way valve; 402. a low pressure shut-off valve; 403. a high pressure shut-off valve; 5. a blower; 501. an inner fan; 502. an external fan; 6. a sensor; 601. an inner coil temperature sensor; 602. an indoor temperature sensor; 603. an outer coil temperature sensor; 604. an outdoor temperature sensor; 605. a high-pressure sensor; 606. a low pressure sensor; 607. an exhaust gas temperature sensor; 608. an air return temperature sensor; 609. a temperature sensor in the middle of the outer coil; 7. a throttle capillary.
Detailed Description
In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
An intelligent oil return control method of a compressor comprises the following steps:
step S1, starting the compressor and continuously operating t 0 After the time, intelligent oil return control is carried out;
step S2, measuring the oil level H of lubricating oil in an oil separator;
step S3, controlling the operation frequency f of the compressor according to the oil level height H.
In the intelligent oil return control method of the compressor, intelligent oil return control is not performed immediately after the compressor is started, and the intelligent oil return control is performed after the compressor is started, so that the compressor is unstable in operation and in an unstable starting operation state in a period of time just after the compressor is started, the accuracy of oil return control is affected when the intelligent oil return control is performed, the time t0 is generally short, the risk of poor oil return of the compressor is low, and therefore the intelligent oil return control is performed after the compressor is started and continuously operated for the time t 0.
Typically, the value of t0 is 3 to 5 minutes.
Furthermore, the oil level H of the lubricating oil in the oil separator is measured, and then the operating frequency f of the compressor is controlled in real time according to the oil level H, so that the operating frequency f of the compressor is closely combined with the oil level H of the lubricating oil in the oil separator, and is closely related to the oil level H, oil return is carried out according to the proper frequency only when oil return is needed, and the problems of high energy consumption, poor reliability and low comfort caused by the fact that forced oil return is carried out blindly according to the parameters such as the operating time, the operating frequency, the exhaust temperature, the air inlet temperature, the exhaust pressure and the exhaust volume of the compressor in the prior art are avoided, and the problems of oil return when oil return is not needed, oil return is not needed and the compressor needs to be quickly switched to high-frequency operation in the oil return process are solved.
Further, in the step S2, the oil level H of the lubricating oil in the oil separator is measured by an oil level sensor.
Specifically, the oil level sensor is disposed in an oil separator, the oil level sensor includes a positive electrode and a negative electrode, and lubricating oil in the oil separator has conductivity.
The working principle of the oil level sensor is as follows: when lubricating oil exists between the anode and the cathode of the oil level sensor, the anode and the cathode can be conducted through the lubricating oil and current can flow through the lubricating oil due to the conductivity of the lubricating oil; when no lubricating oil exists between the anode and the cathode of the oil level sensor, the anode and the cathode are disconnected, no current passes, so that whether the lubricating oil exists between the anode and the cathode or not can be judged according to the on-off state of the oil level sensor, and the oil level H in the oil separator is further obtained.
Further, a plurality of oil level sensors are provided in the oil separator, and the plurality of oil level sensors are distributed at different heights in the vertical direction.
Further, the control unit of the variable frequency air conditioner can judge the oil level height H in the oil separator according to the on-off states of the oil level sensors in the oil separator.
Specifically, the oil level H in the oil separator is determined to be prioritized based on the highest oil level in the on oil level sensor and the lowest oil level in the off oil level sensor, and the oil level H in the oil separator is between the highest oil level in the on oil level sensor and the lowest oil level in the off oil level sensor.
Preferably, 4 oil level sensors are arranged in the oil separator, and the installation heights of the 4 oil level sensors are H1, H2, H3 and H4 respectively, wherein H1 > H2 > H3 > H4:
when the states of the 4 oil level sensors are: the oil level sensors with the heights H1, H2, H3 and H4 are all on, and among the oil level sensors with the heights H1, H2, H3 and H4, the oil level indicated by the oil level sensor with the height H1 is the highest, so the oil level height H in the oil separator is: h is more than or equal to H1;
when the states of the 4 oil level sensors are: the oil level sensors with the height of H1 are disconnected, the oil level sensors with the heights of H2, H3 and H4 are all conducted, and the oil level indicated by the oil level sensor with the height of H2 is the highest among the oil level sensors with the heights of H2, H3 and H4, so that the oil level height H in the oil separator is between H1 and H2, namely the oil level height H in the oil separator is: h1 is more than H and is more than or equal to H2;
when the states of the 4 oil level sensors are: the oil level sensors with the heights H1 and H2 are off, the oil level sensors with the heights H3 and H4 are on, the oil level indicated by the oil level sensor with the height H3 is highest among the oil level sensors with the heights H3 and H4, and the oil level indicated by the oil level sensor with the height H2 is lowest among the oil level sensors with the heights H1 and H2, so the oil level height H in the oil separator is between H2 and H3, that is, the oil level height H in the oil separator is: h2 is more than H and is more than or equal to H3;
when the states of the 4 oil level sensors are: the oil level sensors with the heights H1, H2 and H3 are off, the oil level sensor with the height H4 is on, and the oil level indicated by the oil level sensor with the height H3 is the lowest among the oil level sensors with the heights H1, H2 and H3, so that the oil level H in the oil separator is between H3 and H4, that is, the oil level H in the oil separator is: h3 is more than H and is more than or equal to H4;
when the states of the 4 oil level sensors are: the oil level sensors having the heights H1, H2, H3, and H4 are all off, and among the oil level sensors having the heights H1, H2, H3, and H4, the oil level indicated by the oil level sensor having the height H4 is the lowest, and therefore, the oil level height H in the oil separator is lower than H4, that is, the oil level height H in the oil separator is: h4 > H.
Further, in the step S3, the process of controlling the operating frequency f of the compressor according to the oil level height H includes:
the oil level height H is compared with preset values H1, H2, H3 and H4,
when the oil level height H is more than or equal to H1, the compressor does not perform frequency-boosting oil return;
when the oil level height H1 is more than H and is more than or equal to H2, the compressor returns oil at regular time, and the oil return frequency is f3;
when the oil level height H2 is more than H and is more than or equal to H3, the oil is returned to the compressor at regular time, and the oil return frequency is f4;
when the oil level height H3 is more than H and is more than or equal to H4, the oil is returned to the compressor at regular time, and the oil return frequency is f5;
when the oil level height H4 is more than H, the compressor immediately returns oil, and the oil return frequency is f5;
wherein, H1, H2, H3 and H4 are the installation heights of 4 oil level sensors arranged in the oil separator, and H1 is more than H2 is more than H3 and more than H4; and f3, f4 and f5 are preset frequency values, and f3 is smaller than f4 and smaller than f5.
Preferably, the H1 is the height of the pipe orifice of the air outlet pipe in the oil separator, that is, the oil level sensor with the installation height of H1 is flush with the pipe orifice of the air outlet pipe in the oil separator.
In the step S3, H1 is the maximum oil level, when the oil level H is equal to or greater than H1, it indicates that the oil in the oil separator reaches the maximum, and is level with the orifice of the outlet pipe of the oil separator or exceeds the outlet orifice, which indicates that most of the oil carried out from the inlet pipe gradually accumulates at the bottom of the oil separator, and the oil can quickly return to the air return pipe of the compressor in a large amount through the outlet pipe and the oil return capillary, and then returns to the oil tank of the compressor through the air suction port of the compressor, so that the amount of the oil deposited in the condenser, the evaporator and the connecting pipe is extremely small, and the oil can quickly and effectively return to the compressor without oil return risk, and the timing frequency-raising oil return control of the compressor is not required.
Preferably, the H2 is higher than the height of the bearing surface on the rotor in the compressor, that is, the installation position of the oil level sensor with the installation height H2 is higher than the position of the bearing surface on the rotor in the compressor.
Specifically, the oil quantity in the oil separator corresponding to the H2 is the oil quantity in the compressor corresponding to the bearing surface on the rotor, which is the lower limit of the oil quantity for ensuring the normal operation of the compressor when different compressors are in a factory state, and the timing oil return time is consistent with the prior art, and the oil return time is consistent with the prior art.
In step S3, H2 is the intermediate oil level height. As some embodiments of the application, when the oil level is higher than H and equal to H2, the oil in the oil separator reaches an intermediate value at the moment, which means that more oil carried out from an air inlet pipe of the oil separator gradually accumulates at the bottom of the oil separator, the oil rapidly returns to the compressor only through an oil return capillary, which means that the amount of deposited oil in the condenser, the evaporator and the connecting pipe is smaller at the moment, but the oil can effectively return to the compressor through the oil return capillary, so that the normal operation of the compressor is satisfied, the oil return risk is lower, the compressor only needs to return oil regularly, the value of the oil return frequency f3 can be lower, and the value of the oil return frequency f3 is 60-65 Hz.
Preferably, the H3 is higher than the height of the bearing surface on the rotor in the compressor, that is, the installation position of the oil level sensor with the installation height H3 is higher than the position of the bearing surface on the rotor in the compressor, and the installation position of the oil level sensor with the installation height H3 is lower than the installation position of the oil level sensor with the installation height H2.
Specifically, the oil quantity in the oil separator corresponding to H3 is the oil quantity in the compressor corresponding to the bearing surface on the rotor, which is the lower limit of the oil quantity of the compressor capable of operating normally when different compressors are in a factory state, and the timing oil return time is consistent with the prior art, and the oil return time is consistent with the prior art.
In the step S3, H3 is a lower oil level height. As some embodiments of the application, when the oil level is higher than H2 and more than or equal to H3, the oil content in the oil separator reaches the lowest value, which indicates that the deposited oil content in the condenser, the evaporator and the connecting pipe is more, and the risk of poor oil return exists, the compressor must normally perform timing oil return at a higher oil return frequency f4, and preferably, the value of the oil return frequency f4 is 68-72 Hz.
Preferably, the H4 is equal to the height of the lower bearing surface of the rotor in the compressor, that is, the installation position of the oil level sensor with the installation height H4 is equal to the position of the lower bearing surface of the rotor in the compressor.
Specifically, the oil quantity in the oil separator corresponding to H4 is the oil quantity in the compressor corresponding to the bearing surface under the rotor when different compressors leave the factory, and the oil quantity reaches the upper limit of the abnormal oil quantity of the oil return of the compressor, and the timing oil return time is consistent with the prior art, and the oil return time is consistent with the prior art.
In the step S3, H4 is the lowest oil level. As some embodiments of the application, when the oil level is higher than H3 and equal to or greater than H4, the oil amount in the oil separator reaches the minimum value, which indicates that the oil amount deposited in the condenser, the evaporator and the connecting pipe is large at the moment, and the risk of poor oil return exists, the compressor must normally perform timing oil return at the highest oil return frequency f5, and preferably, the oil return frequency f5 has a value of 75-80 Hz.
As some embodiments of the application, when the oil level is higher than H4, the oil amount in the oil separator reaches the minimum value at this time, which indicates that the oil amount deposited in the condenser, the evaporator and the connecting pipe is large at this time, and serious bad oil return risks exist, the compressor must immediately return oil at the highest oil return frequency f5, at this time, the bad oil return risks are high, the oil return needs to be immediately increased, the timing requirement is not required, and preferably, the value of the oil return frequency f5 is 75-80 Hz.
Further, in the step S3, when the oil level height H1 > H is greater than or equal to H2, when the oil level height H2 > H is greater than or equal to H3, and when the oil level height H3 > H is greater than or equal to H4, the compressor needs to perform timing oil return, and the timing oil return process includes: when the running frequency f of the compressor is lower than the accumulated time of the preset threshold f1 and reaches t1 time, the compressor enters into the ascending oil return operation, and the oil return time is t2 each time.
Preferably, the value range of f1 is 50-55 Hz, the value range of t1 is 3-4 h, and the value range of t2 is 4-6 min.
It should be noted that the timer of the accumulated time of the compressor operation frequency lower than f1 is not cleared and only stops during the mode conversion, the manual shutdown or the protective shutdown. When the compressor is restarted, the timing is continued.
In addition, during the time period of the accumulated time when the operation frequency of the compressor is lower than f1, if the time that the operation frequency of the compressor is continuously more than or equal to f2 reaches t3 time, the time is cleared, and the compressor is substantially subjected to the frequency-up oil return.
Preferably, the value range of f2 is 70-80 Hz, and the value range of t3 is 5-8 min.
In the prior art, the running state of the compressor is controlled through timing oil return, for example, when the compressor meets the oil return condition and enters the ascending oil return running process, the controller of the air conditioner sends an oil return signal to the compressor, the compressor starts oil return after a period of time, for example, 60S, of receiving the oil return signal, at this time, the compressor runs at an oil return frequency, for example, 72Hz, the external fan PMV keeps 350 pulse running, the external fan and the internal fan automatically run, the four-way valve is closed, the oil return is continued for a period of time, for example, after 4min, the oil return is finished, and then the compressor, the external fan, the internal fan and the four-way valve are normally controlled.
In step S3 of the present application, when the compressor needs to be controlled to perform oil return, the control process of the air conditioner is similar to the prior art, for example, when the compressor meets the oil return condition and enters the ascending oil return operation process, the controller of the air conditioner sends an oil return signal to the compressor, after a period of time when the oil return signal is received, for example, 60S, the compressor starts oil return, at this time, the compressor operates at an oil return frequency, for example, 72Hz, the external machine PMV keeps 350 pulse operation, the external fan and the internal fan operate automatically, the four-way valve is closed, and in the oil return state, for example, after 4min, the oil return is completed, and then the compressor, the external machine PMV, the external fan, the internal fan and the four-way valve are controlled normally.
In summary, according to the intelligent oil return control method of the compressor, on the control logic of the existing compressor, through arranging a plurality of corresponding oil level sensors on the side wall, such as the outer wall or the inner wall, of the oil separator corresponding to the oil levels at different heights, the oil level state interval of the oil level in the oil separator is judged in real time through the on/off state of the oil level sensors, the oil return control for differentiating the oil return frequency corresponding to the difference of the different oil level heights H is further increased, and the different oil return frequencies are controlled according to different oil level intervals of the oil level in the separator, so that the comfort, the energy conservation and the reliability of the oil return process are ensured to the greatest extent.
In addition, in the intelligent oil return control method of the compressor, the oil level state interval of the oil level in the oil separator is judged through the oil level sensor, so that the intelligent oil return control method is low in cost, simple in structure and high in floor type.
In addition, as shown in fig. 2 to 6, the present application also provides a variable frequency air conditioner, the air conditioner comprising: the evaporator comprises an evaporator 1, a condenser 2, a compressor 3, a control valve 4, a fan 5 and a throttle capillary tube 7, wherein the control valve 4 comprises a four-way valve 401, a low-pressure stop valve 402 and a high-pressure stop valve 403, one end of the evaporator 1 is connected with one port of the four-way valve 401 through the low-pressure stop valve 402, the other end of the evaporator is connected with one end of the throttle capillary tube 7 through the high-pressure stop valve 403, the other end of the throttle capillary tube 7 is connected with one end of the condenser 2, the other end of the condenser 2 is connected with the other port of the four-way valve 401, and the remaining two ports of the four-way valve 401 are respectively connected with an air inlet and an air outlet of the compressor 3.
Further, the compressor 3 includes a compressor body 301, an oil separator 302, a gas separator 303, and an oil return capillary tube 304, one end of the gas separator 303 is connected to one port of the four-way valve 401, the other end is connected to the oil return capillary tube 304 and an air return port of the compressor body 301, the other end of the oil return capillary tube 304 is connected to an oil return pipe 3022 of the oil separator 302, an exhaust port of the compressor body 301 is connected to an air inlet pipe 3029 of the oil separator 302, and an air outlet pipe 3021 of the oil separator 302 is connected to another port of the four-way valve 401.
Further, the fan 5 includes an inner fan 501 and an outer fan 502, the inner fan 501 is located in the indoor unit of the variable frequency controller, and the outer fan 502 is located in the outdoor unit of the variable frequency controller.
Further, the variable frequency controller further comprises a plurality of sensors 6, and parameters such as temperature, pressure and the like can be detected through the sensors 6.
Specifically, the sensor 6 includes:
an inner coil temperature sensor 601 provided on a coil of the evaporator 1 to detect a coil temperature in the evaporator 1;
an indoor temperature sensor 602, which is disposed in an indoor unit of the inverter air conditioner, and is used for detecting an indoor temperature;
an outer coil temperature sensor 603 provided on a coil of the condenser 2 to detect a coil temperature in the condenser 2;
an outdoor temperature sensor 604 provided in an outdoor unit of the inverter air conditioner for detecting an outdoor temperature;
a high pressure sensor 605 provided at an exhaust port of the compressor 3 to detect an exhaust pressure of the compressor 3;
a low pressure sensor 606, which is disposed at the return air port of the compressor 3, and is used for detecting the return air pressure of the compressor 3;
an exhaust gas temperature sensor 607 provided at an exhaust port of the compressor 3 for detecting an exhaust gas temperature of the compressor 3;
and a return air temperature sensor 608 provided at a return air port of the compressor 3 for detecting a return air temperature of the compressor 3.
Still further, the sensor 6 further includes an outer coil middle temperature sensor 609 disposed on the coil in the middle of the condenser 2 for detecting the coil temperature in the middle of the condenser 2.
Further, the oil separator 302 includes: the upper end cover 3027, the middle cylinder 3024 and the lower end cover 3023 which are sequentially arranged from top to bottom, wherein the upper end cover 3027, the middle cylinder 3024 and the lower end cover 3023 are connected with each other to form an outer shell of the oil separator 302, an air inlet pipe 3029 is inserted into the upper end of the oil separator 302, an air outlet pipe 3021 and an oil return pipe 3022 are inserted into the lower end of the oil separator 302, a first filter screen 3025 and a second filter screen 3028 are further arranged in the oil separator 302, and SUS wires 3026, namely stainless steel wires, are arranged between the first filter screen 3025 and the second filter screen 3028.
In operation, the gas discharged from the compressor body 301 enters the oil separator 302 through the gas inlet pipe 3029, is separated by the first filter screen 3025 and the second filter screen 3028, is discharged through the gas outlet pipe 3021, and the lubricating oil is deposited in the oil separator 302 and is discharged through the oil return pipe 3022.
Further, 4 oil level sensors are arranged on the side wall of the oil separator 302, the 4 oil level sensors are respectively arranged at the positions with the heights of H1, H2, H3 and H4 in the oil separator 302, the oil level sensors comprise a positive electrode and a negative electrode, and when lubricating oil exists between the positive electrode and the negative electrode of the oil level sensor, the positive electrode and the negative electrode can be conducted through the lubricating oil due to the conductivity of the lubricating oil, and current can flow through the positive electrode and the negative electrode; when no lubricating oil exists between the anode and the cathode of the oil level sensor, the anode and the cathode are disconnected, and no current passes.
When the variable frequency air conditioner works, most of oil carried out from the exhaust port of the compressor 3 is filtered in the oil separator 302, and the oil is gradually collected and deposited at the lower part of the oil separator 302 under the filtering, depositing and gravity depositing actions of the first filter screen 3025 and the second filter screen 3028, and an oil return pipe 3022 is connected with an oil return capillary 304, so that the action of the oil return capillary 304 is throttled and depressurized on one hand, and the phenomenon that too much high-temperature refrigerant enters the air return to cause large performance loss is avoided; on the other hand, the oil return resistance is increased, the oil return quantity is controlled, the performance is considered, and the oil deposited at the lower part of the oil separator 302 is returned to the compressor 3 through the air return port due to the pressure difference of the exhaust and the air return, so that the reliability of the oil return of the system is improved.
Although the present application is disclosed above, the present application is not limited thereto. In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the application, and the scope of the application should be assessed accordingly to that of the appended claims.
Claims (8)
1. The intelligent oil return control method of the compressor is characterized in that in the compressor, an exhaust port of a compressor body is connected with an air inlet pipe at the upper end of an oil separator, the lower end of the oil separator is inserted into an air outlet pipe and an oil return pipe, the air outlet pipe is connected with a four-way valve, and the oil return pipe is connected with an air return port of the compressor body through an oil return capillary pipe, and the method comprises the following steps:
step S1, after the compressor is started and continuously runs for t0 time, intelligent oil return control is performed;
step S2, measuring the oil level H of lubricating oil in an oil separator;
step S3, controlling the operation frequency f of the compressor in real time according to the oil level height H, so that the operation frequency f of the compressor is closely combined with the oil level height H of lubricating oil in the oil separator, and oil return is carried out according to proper frequency only when oil return is needed;
when the oil level H in the oil separator is divided into 5 state sections, the oil level H is sequentially from high to low: when H is greater than or equal to H1, H1 is greater than or equal to H2, H2 is greater than or equal to H3, H3 is greater than or equal to H4 and H4 is greater than or equal to H, in the step S3, the process of controlling the operating frequency f of the compressor in real time according to the oil level height H comprises the following steps:
when the oil level height H is more than or equal to H1, the compressor does not perform frequency-boosting oil return;
when the oil level height H1 is more than H and is more than or equal to H2, the compressor returns oil at regular time, and the oil return frequency is f3;
when the oil level height H2 is more than H and is more than or equal to H3, the oil is returned to the compressor at regular time, and the oil return frequency is f4;
when the oil level height H3 is more than H and is more than or equal to H4, the oil is returned to the compressor at regular time, and the oil return frequency is f5;
when the oil level height H4 is more than H, the compressor immediately returns oil, and the oil return frequency is f5;
wherein f3, f4 and f5 are preset frequency values, f3 is smaller than f4 and f5, and the process of timing oil return of the compressor comprises the following steps:
1) When the running frequency f of the compressor is lower than the accumulated time of the preset threshold f1 and reaches t1 time, the compressor enters into the ascending oil return operation, and the oil return time is t2 each time;
2) When the mode is switched, the operation is stopped manually or in a protective stop process, the timing of the accumulated time with the operation frequency lower than f1 of the compressor is not cleared, only the timing is stopped, and the timing is continued after the compressor is restarted;
3) And in the timing period of the accumulated time with the compressor running frequency lower than f1, if the time with the compressor running frequency continuously more than or equal to f2 reaches t3 time, indicating that the compressor has substantially performed the frequency-up oil return, and resetting the timer.
2. The intelligent oil return control method of a compressor according to claim 1, wherein in said step S2, the oil level H of the lubricating oil in the oil separator is measured by an oil level sensor.
3. The intelligent oil return control method according to claim 2, wherein,
the oil level sensor is arranged on the oil separator and comprises a positive electrode and a negative electrode, and lubricating oil in the oil separator has conductivity;
when lubricating oil exists between the anode and the cathode of the oil level sensor, the oil level sensor is conducted;
and when no lubricating oil exists between the anode and the cathode of the oil level sensor, the oil level sensor is disconnected.
4. The intelligent oil return control method according to claim 3, wherein a plurality of oil level sensors are arranged in the oil separator, the plurality of oil level sensors are distributed at different heights along the vertical direction, and the control unit of the variable frequency air conditioner judges the oil level height H in the oil separator according to the on-off states of the plurality of oil level sensors.
5. The intelligent oil return control method according to claim 4, wherein the oil level height H in the oil separator is between a highest oil level in the on oil level sensor and a lowest oil level in the off oil level sensor.
6. The intelligent oil return control method according to claim 5, wherein 4 oil level sensors are arranged in the oil separator, the installation heights of the 4 oil level sensors are H1, H2, H3 and H4 respectively, wherein H1 > H2 > H3 > H4, the oil level height H in the oil separator is divided into 5 state intervals according to the on-off states of the 4 oil level sensors, and the intervals are sequentially from high to low: h is more than or equal to H1, H1 is more than or equal to H2, H2 is more than or equal to H3, H3 is more than or equal to H4 and H4 is more than or equal to H.
7. The intelligent oil return control method according to claim 1, wherein the oil return frequency f3 has a value of 60-65 Hz; the value of the oil return frequency f4 is 68-72 Hz; the value of the oil return frequency f5 is 75-80 Hz.
8. A variable frequency air conditioner, characterized in that the variable frequency air conditioner adopts the intelligent oil return control method of any one of the claims 1-7 to return oil to a compressor.
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| JPS6458970A (en) * | 1987-08-31 | 1989-03-06 | Mitsubishi Electric Corp | Heat pump type air conditioner |
| CN104596023A (en) * | 2013-10-30 | 2015-05-06 | Lg电子株式会社 | AIR CONDITIONER AND METHOD thereof |
| CN110595110A (en) * | 2019-09-30 | 2019-12-20 | Tcl空调器(中山)有限公司 | Air conditioner oil return control method and system, storage medium and air conditioner |
| CN111648951A (en) * | 2020-06-16 | 2020-09-11 | 龙川纽恩泰新能源科技发展有限公司 | Compressor with oil level detection function and automatic oil return and oil supplement heat pump system |
-
2022
- 2022-02-18 CN CN202210152528.5A patent/CN114427745B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6458970A (en) * | 1987-08-31 | 1989-03-06 | Mitsubishi Electric Corp | Heat pump type air conditioner |
| CN104596023A (en) * | 2013-10-30 | 2015-05-06 | Lg电子株式会社 | AIR CONDITIONER AND METHOD thereof |
| CN110595110A (en) * | 2019-09-30 | 2019-12-20 | Tcl空调器(中山)有限公司 | Air conditioner oil return control method and system, storage medium and air conditioner |
| CN111648951A (en) * | 2020-06-16 | 2020-09-11 | 龙川纽恩泰新能源科技发展有限公司 | Compressor with oil level detection function and automatic oil return and oil supplement heat pump system |
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